Sorting arrangement



United States Patent 2,993,596 SORTING ARRANGEMENT Karl Stembnch, Fellbach, Wurttemberg, Germany, as-

signor to International Standard Electric Corporation, New York, N.Y., a corporation of Delaware F led June 5, 1957, Ser. No. 663,703 Claims priority, application Germany June 12, 1956 8 Claims. (Cl. 209-1115) This invention relates to switch control arrangements and more particularly to the control of switches in article conveying and sorting systems.

In article sorting arrangements, apparatus must be provided to remove articles from the conveyor in accordance with indicia either applied to the article or according to size, etc. Switches or rejecting devices are commonly used to eflFect the transfer of an article from a conveyor and these switches must be controlled so as to operate at the correct moment in order to remove a given article from the conveyor. It is to apparatus which controls the operation of such switches that this invention is directed.

This invention may be used in conjunction with a switching arrangement shown, for instance, in the copending application of W. Sindzinski entitled Conveyor System, filed December 9, 1953, and bearing Serial Number 397,106 and now Patent Number 2,806,582. It should be clearly understood, however, that this invention may control any other suitable switching system and is to be deemed limited only to the extent defined by the claims appended hereto.

Applicants invention is an electronic control arrangement which derives control signals from a particular characteristic of an article and thereafter derives additional control signals from the passage of an article along the conveyor system and which signals control the switching apparatus.

Applicant chooses to describe this invention in connection with a mail sorting arrangement but it should be understood that the invention is not limited solely to such a sorting arrangement. The invention may be applied to bookkeeping devices, bank check sorting arrangements, card statistic sorting devices and the like. In postal work, special problems of sorting arise because letters must be sorted according to their destination. In order to enable an operator to properly route the letter to its destination, it is necessary that he be enabled to read the written address on the letter envelope. This maybe diificult, inasmuch as a letter may assume any one of four positions on a conveyor system of which only one is readable by the operator. Accordingly it is necessary to first sort the letters according to their position so that the letter will be separated into four groups and the separated groups may then be combined in a uniform manner. With conventional sorting arrangements, the articles to be sorted are provided with indicia which may be sensed and then guided to a particular compartment under the control of suitable sensing devices. Photo electric sensing is known and unless the device is equipped with some register to record information regarding the destination of the card sensed, and in the further event that the sensed card is destined to one of the remote positions along the sorting system, the operating speed of the system is relatively low in comparison to such systems in which storage of destination information is provided. In order to augment the efficiency of the arrangement without increasing the travelling speed of the conveyor, provision must be made to permit several articles to travel on the conveyor simultaneously. This necessitates that a switch may be set only when the article destined to be switched from a conveyor has reached that particular switch. To achieve this last Patented July 25., 1961 moment switch operation it is necessary to delay operation of the proper switch. The prior art utilize mechanical timing elements to achieve the necessary delay, but these were unsatisfactory. The present invention solves the problem of operating the switches immediately prior to the arrival of the article destined to be switched thereby and provides a plurality of storage devices, one for each switch, each of which is advanced by pulses created by the article itself as it proceeds along the conveyor system subject to having been selected by an indicia detecting device along the path of the conveyor system preceding the first switch.

Accordingly, it is the object of the invention to provide a switch control circuit in a conveyor system by the use of individual registers allocated to each switch capable of evaluating the progress of an article along the conveyor system, with means to select a register associated with a particular switch in accordance with indicia car-' ried by the article.

It is another object of the invention to provide a series of switches along the length of a conveyor for launching articles therefrom in accordance with destination char.- acteristics carried thereon and which characteristics are read and evaluated at the input of the sorting arrangement and to produce diiferent signals in accordance with those characteristics whereby they select a storage device associated with a switch to be operated and to derive electrical signals from the passage of the article along the conveyor system to advance the storage device and to actuate said switch when said storage device has reached a predetermined condition.

The above-mentioned and other features and objects of this invention and the manner of attaining them will become more apparent and the invention itself will be best understood, by reference to the following descrip: tion of an embodiment of the invention taken in conjunction with the accompanying drawing, wherein:

The sole figure is a schematic representation of a con: veyor system, including the sensing device, the switches and the storage devices assigned to the respective switches. As stated before, applicant chooses to explain this invention in connection with a letter sorting arrange-i ment. There is shown schematically in the drawing a conveyor belt 2 which is adapted to be moved in the direction of the arrow by motive means (not shown) and is adapted to carry thereon letters AR which are to be distributed to the receiving stations C1 C4 in ac-. cordance with the position of the stamp on the envelope of the letter. It should be explained that the stamp may be in the upper right-hand corner of the letter as shown in the drawing or if the letter is reversed in this posi-' tion it will be at the lower left-hand corner. If the re-, verse side of the envelope faces the reader then the stamp may be in similar shifted positions, namely 180". In order to read both sides of the envelope, there is shown schematically a sensing device 1 having four photo ele'c tric devices PE1 PEA, each photo electric device being directedto receive reflected light from the respective four stamp positions above enumerated. A suitable light source is provided on either side of the conveyor with which said cells may cooperate. The passage of a colored stamp in the path of a photo electric cell will cause a pulse to be derived from the particular photo electric cell and which pulses may be amplified and will appear on the output leads R1 R4, depending upon which cell was excited. The device 1, therefore, is a sensing device to sense the characteristics of the letters. Further along the conveyor belt 2 there are four recep-v tacles C1 C4 each of which is adapted to receive envelopes with the stamps in the four positions, respectively. Adjacent the receptacles there is provided an article ejecting switch W1 W4, respectively, each switch when actuated being of a letter from the belt 2 to its associated receptacle. Preceding the switches there are provided article detecting elements S1 S4, respectively, each of which is adapted to cooperate with a light source LS and each of which is adapted to deliver a first electrical output pulse upon the passage of each letter on the belt in front of the element regardless of its destination. The elements 81 .84 are adapted to deliver another pulse upon the passage of the letter beyond the element and which pulses appear respectively on the a and the e leads of said devices. The apparatus for performing this function may be, for example, a photo electric cell coupled to the input of an amplifier and having the output of the amplifier coupled to a difierentiating circuit to provide the respective a and e pulses, one for each change of condition of its associated photo electric device. 7 The switches W1 W4 have associated therewith individual register or storage devices A1 A4, respectively. These storage devices consist of two or more stages. Thus 'it will be seen that the first storage device A1 associated with switch W1 consists of two stages F11 and F21. .The second register A2 associated with the switchv W2 consists of three stages F12, F22 and F32. The registers A3 and A4 consist of four and five stages, respectively. 'Each stage of the storage devices consist of a'bi-stable switching device known in the art as flipflop circuits and have the characteristic quality which enables them to maintain a given switch position until changed upon receipt of a changeover pulse. These devices are well known to those skilled in the art and need no further explanation here. It is customary in the artto indicate each portion of a flip-flop circuit with a 1 and a'0. In the arrangement here disclosed, it is assumed that. each stage of each of the storage device A1 A4 initially have conducting the portions. The inputs to the first stages of storage devices A1 A4, namely F11, F12, F13 and F14 are adapted to have coupled thereto the outputs R1 .,R4 from the scanning device 1, as shown, by the terminals -R1 R4. This coupling is to the 1 portions of the stages. Each of the'0 portions of the same stages are connected to a common bus L1 to which the output SIA'from the device S1 is adapted to be applied. The output portion of each portion 1 of eachstage is adapted to be coupled to the input ofthe 1 portion of the next succeeding stage. Theportions 1 are adapted to give an output when they are flipped, that is, when the 0 portions are rendered conducting. The output 32A is adapted to be applied in common to the 0, portions of the second stages of registers A2, A3 and A4 over the common bus L2. 'Bus L3 is adapted to apply the outputS3A to stages F33 and F34. Bus L4 isadapted to apply theoutput 84A to the stage F44. The 0 portions of the final s tages in registers A1. A4 are connected to the outputs Sl S42, respectively. The output of the 1 portion of the last stage in each register is connected to switch actuating apparatus SAA1 SAA4. Each of the last mentioned apparatuses is adapted .to control the movement of its associated switch W1 W4.

The operation of the device will now be described. It will be assumed that initially each of the 0 portions of allthe registers A1 A4 are conducting. Let it be assumed that theletter AR carried by the belt 2 has its stamp sensed by the photo electric devicePE3 as a result of .which an output pulse R3 is derived from the unit 1. This pulse isapplied to the first stage-of register A3 and causes the 1 portion to conduct and renders the 0 portion to become non-conducting. It will be remembered that all the other 0 portions of the first stages of the other registers are conducting. With further movement of the belt 2, the leading edge of the envelopeAR causes a first output pulse to be derived from the-device S1 and which output pulse is applied to the common bus L1. The stageF13 wil1 reverse its conduction pattern,

adapted to cause the removal 4 I namely the 0 portion will reconduct and the l portion will become non-conducting and an output pulse will be derived therefrom over lead L to be applied to the 1 portion of the second stage F23 of the register A3.

5 Thus the count in register A3 is advanced one stage. It

will be noted that registers A1, A2 and A4 remain unaffected since their 0 stages were already conducting and therefore the pulse SlA caused no change in their conducting condition. As the trailing edge of the letter AR passes the device S1, the output pulse 51E is developed and is applied to the 0 portion of the stage P21 in register A1. This, however, is of no effect since the 0 portion is already conducting and consequently the switch actuating apparatus SAA1 remains unactuated. Switch W1 remains unactuated and the letter AR passes beyond same into the vicinity of the second device S2 which immediately precedes the switch W2. The leading edge of the envelope produces the output pulse 82A and which pulse is applied to the bus L2. Since all the 0 portions in the register A1, A2 and A4 are conducting and since only the 0 portion of the stage P23 is non-conducting, the stage F23 will reverse its conduction pattern and a pulse will be applied to the next stage F33. If an envelope passes device S2 and its trailing edge causes the pulse at 82E to be developed, this pulse which is applied to the last stage F32 of the register A2 causes no change in the conduction pattern thereof and switch actuating apparatus SAAZ remains un-operated. The envelope AR now approaches the device S3 and its leading edge causes a pulse 83A to be applied to the bus L3. This pulse causes the stage F33 to flip and output is passed along to the final stage F43 and the lip'o-rtionof that said final stage is rendered conducting. As the trailing edge of the envelope causes the generation of the pulse 83E, this pulse is applied to the 0 portion of the stage F43 causing it to re-conduct and the non-conduction of the 1 portion thereof. The non-conduction of the 1 portion causes an output pulse to be appliedto the switch actuating apparatus SAA3, causing the operation of the switch W3 and the letter AR is shunted from the belt by the operation of the switch into the receptacle C3.

The e pulse also constitutes a re-set pulse and after the delivery of the letter into its associated'receptacle, each of the stages are in the initial condition that is to say the 0 portions are again conducting and are ready to respond to the next letter to appear on the belt 2. If four successive letters appear on the belt 2, each in one of the four different positions, all four of the registers may be caused to step and the leading edge of each letter will act to step each stage of each register simultaneously. The distance between individual letters on the conveyor belt should be either equal to or greater than the distance of the spaces between adjacent switches. It will be appreciated that a switch control direction may be stored in a succeeding storage device before the storage device associated with the switch directly behind it has been cleared.

The arrangement disclosed may be adapted to sort for more than four possible conditions by providing additional sensing devices to seize the desired register. It will be understood, of course, that there must be N +1 stages for such additional registers. Thus the addition of a plurality of registers would render this invention capable of sorting punch cards or. other items bearing distinctive indicia. It will also be understood that the selection of the desired register can be effected by an operator manually by manipulation of switches which apply pulses that are the equivalent of the pulses R1 R Thusthis device may be used in conjunction with the sorting arrangement disclosed in the co-pending application of A. Mehlis, entitled Arrangement to Inspect Stacked Legendized Papers, in Particular to Read the Addresses of Stacked Letters, filed May 27, 1957, hearing Serial Number 661,757, and now Patent Number 2,889,941. 7

While I have described above the principles of my invention in connection with specific apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation to the scope of my invention as set forth in the objects thereof and in the accompanying claims.

What is claimed is:

l. A control arrangement for an article sorting system of the type having a conveyor means and a plurality of ejection paths spaced along the conveyor, comprising a plurality of switch means to select an associated ejection path, a plurality of electrical pulse producing means, one for each of said switch means, each located immediately before its associated switch, each adapted to be actuated by an article proceeding along the conveyor, a plurality of switch actuating means, each associated with a different one of said switches and adapted to control operation thereof, a plurality of multistage storage means, each associated with a different one of said switch actuating means, each having corresponding stages coupled to a corresponding one of said pulseproducing means, a plurality of seizure-signal producing means, each coupled to a difierent one of said storage means, each adapted to seize its corresponding storage means, and each disposed along the conveyor ahead of the pulse producing means coupled to the same storage means and adapted to be actuated by a predetermined article proceeding along the conveyor, said pulse producing means adapted to simultaneously advance storage of information in each of said storage means after seizure thereof by the associated seizure-signal producing means, separate intercoupling means between adjacent stages of each of said storage means, coupling means between each ultimate stage of said storage means and its associated switch actuating means and a plurality of re-set means, each associated with different ones of said ultimate stages, each under control of different ones of said pulse-producing means, whereby operation of a switch actuating apparatus causes operation of its associated switch means and operation of said re-set means returns said storage means to its unseized condition.

2. A control arrangement as claimed in claim 1, wherein each of said storage means comprises a plurality of n+1 cascaded storage stages, where n equals the number of the switch means with which the storage means is associated.

3. A control arrangement as claimed in claim 2, where in each of said stages comprises a bi-stable circuit.

4. A control arrangement as claimed in claim 2, wherein each of said stages comprises a pair of gaseous discharge tubes interconnected in a manner whereby the conduction of one tube results in the non-conduction of the other, these being a 1 tube and a 0 tube.

5. A control arrangement as claimed in claim 4, wherein each of the 1 tubes of the first stage of said storage means are coupled to different ones of said seizure-signal producing means.

6. A control arrangement as claimed in claim 1, wherein said seizure-signal producing means comprises a plurality of photo-electric devices each adapted to produce an output signal upon reading a difierent characteristic of said article.

7. A control arrangement as claimed in claim 1, wherein each of said pulse producing means comprises photoelectric means, each comprising a pair of output terminals and adapted to produce a first pulse at a first of said output terminals upon the entry of said article into the vicinity of said photo-electric means and to produce a second pulse upon the departure of said article from the vicinity thereof at the other output terminal.

8. A control arrangement as claimed in claim 7, further comprising a plurality of interconnections, each interconnection among corresponding intermediate 0 stages of each of said storage means and "a difierent one of said first terminals, respectively, and a connection between difierent ones of the ultimate 0 stages of each of said storage means and a difierent one of said other terminals, respectively.

References Cited in the file of this patent UNITED STATES PATENTS 1,729,521 Roddy Sept. 24, 1929 2,056,382 Ayres et al Oct. 6, 1936 2,592,202 Smith Apr. 8, 1952 2,732,896 Lundahl Jan. 31, 1956 FOREIGN PATENTS 2035271 Australia July 5, 1956 682,303 Great Britain Nov. 5, 1952 

